I went out to the coop this morning to find the girls had physically pushed aside the chicken wire cylinder that had been blocking the nesting box. Evidently, some time between sunset last night and dawn this morning, the lure of the nesting box became to great to ignore and the new contraption was brutally pushed aside to make way.
And to top things off, the girls pooped in the bottom of the nesting box to make sure I knew it was their own doing.
Will have to reinforce it in place tonight. I think I can use the vent holes at the top of the Eglu to anchor the cylinder in place.
I'm not giving up yet!